The statements in this section merely provide background information related to the present disclosure and do not necessarily constitute prior art.
Where a boundary-of-interest is open with connected line segments, a known event monitoring apparatus generates an alarm when a one of the line segments on a monitor is crossed by a moving object. In case the boundary-of-interest is closed with connected line segments, so that it forms a region, the event monitoring apparatus generates an alarm in the event that a moving object enters or exits the region on the monitor.
Various methods have used information on all or a part of the boundary line segments (e.g., both end points of the line or points that consists line segments) and object information (e.g., position or trajectory) in order to detect such an event, or they have used positive or negative sign information of the object location for a boundary region so as to check whether the object is in or outside the region.
However, such event monitoring apparatus in some situation can neither detect various events, nor intuitively determine a sign and a distance of the object simultaneously, thereby causing a surveillance system to suffer from a loading delay.